Acousto-magnetic (AM) technology has been used for electronic article surveillance anti-theft devices. The original concept for an acousto-magnetic label is disclosed in U.S. Pat. No. 4,510,489, granted on Apr. 9, 1985, to Philip M. Anderson, et al, which teaches that certain amorphous alloy strips can generate strong resonating signal due to a high magnetic-elastic exchange coupling factor. Such amorphous alloy strips can be utilized through the disclosed Anderson principle by using such materials in a commercial anti-theft system (AM system), such as the anti-theft systems installed in supermarkets, etc. An AM system includes in detection panel, deactivation and deactivation verifier, and an AM label or tags. A widely used AM detection panel is marketed by Sensormatic Electronics Corporation (Sensormatic) under the brand name of Ultramax. The detection panels can emit 58 kHz pulse field, to exciting the active AM labels in the interrogation zone, to emit very strong signal as the result from resonating at 58 kHz. The signal can be detected by the search coils.
Deactivation is carried out by demagnetizing the bias in the anti-theft AM labels, resulting in the resonating frequency being shifted out of the detection window, meanwhile significantly lowering the resonating amplitude. Therefore, deactivated AM labels will not set off the detection systems. There are two types of AM tags, a hard tag and a soft label. The hard tag uses amorphous ribbon as resonators and uses permanent magnets (such as bonded ferrites) as the bias. This hard tag type of AM Tags, such as Supertags I, II, III made by Sensormatic, cannot be deactivated by deactivators and are used repeatedly inside the stores. The hard tag can be detached mechanically from a locking device so that goods being protected by the hard tag can leave the store without setting off the alarm corresponding to the detection system installed at the gates.
The soft label also uses an amorphous alloy as the resonators, but uses “semi-hard” or “soft” magnetic materials as the bias (e.g. the DR labels made by Sensormatic and T3 labels made by Ningbo Signatronic Technologies, Inc.) This type of AM soft tag can be deactivated and re-activated repeatedly. The AM labels on paid goods are typically deactivated by a deactivator, so that goods can leave the store without triggering the detection system at the gates.
Currently, the flat upper surface of the housing on AM labels can be printed for some patterns, which can serve several purposes. For instance, the AM label supplier can print its own brand name or registered trademark on the upper surface to show the AM label is an authentic product for anti-fake function. Sometime the upper surface can be printed with a fake barcode as a decoy, in hopes that shoplifters would regard this fake barcode as a price barcode and not remove the anti-theft label from the product. Sometimes, retailers intentionally print some anti-theft sign on the upper surface to act as open warning in hopes that the warning can deter shoplifters.
Also, certain retailers request that their logo be printed on the anti-theft labels so that when a dispute arises to determine whether a detector system alarm is caused by the AM labels for that particular retailer store or from a failed deactivated AM label from another store.
However, the shape and appearance of AM labels have not been changed much since its invention in 1982. Currently billions of AM labels, with the familiar supplier logo, and a familiar but monotonous rectangular shape, are used worldwide annually and are well recognizable by consumers. The problem is that shoplifters are also very familiar with such shape, barcode and patterns of these anti-theft labels, which makes it easy for shoplifters to identify these AM labels and try to remove the AM labels from the goods they are attempting to shoplift. As the result, certain retailers are not satisfied with the conventional concealment tactics for the AM labels and have tried new concealment methods for their AM labels, such as hiding the AM label into a commercially used hangtag which is printed with patterns or wordings, or using a plastic overlay with patterns or wordings to cover the AM labels.
However, such double processes cause higher process costs. Furthermore, some AM labels can be partially damaged during such concealment methods, resulting in a lower detection rate. In addition, such solutions do not end up as nice looking products. Consequently, certain retailers would like to have a direct AM label which has a better concealment function, but does not need such double processes. Some retailers would also like a new concealment method that is different from conventional monotonous shaped AM labels to enhance the anti-theft effect. Also, certain retailers would like their logo shown on their goods as well as the AM labels to protect these goods.
It is known in the art to emboss concave and/or convex patterns or wordings on injection molded products. For instance, embossed patterns or wordings are commonly found on hard AM tags with wide applications in the stores and with customers' acceptance. However, AM soft labels are made with thin (about 0.3 mm) PS/PE laminated) plastic film to form the resonator housing by hot forming manufacturing techniques. The upper surface of such a housing is so thin, it is not easy to make fine and nice concave and/or convex patterns or wordings on it. Consequently, there is no report on how to make 3-D patterns or wordings on the upper surface of the housing of AM soft labels, which has prevented the further development on conceal technologies for AM labels.
Accordingly, it would be desirable to provide a soft AM label housing and a method of manufacturing that would provide a quality embossed pattern or word in the upper surface of the housing.